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Hello, does anyone know or has anyone done data(image/video) transfer via infrared laser?
I have transmitted music but not been able to transfer, please help
I have transmitted music but not been able to transfer, please help
Infrared laser image/video transfer
- Thread starter Stephen Kabali
- Start date
yes, NTSC is just fine.
What have you tried?
The main difference between audio and video is the frequencies involved. For NTSC you need about 5 MHz of bandwidth. This is almost 1000 times higher than audio.
The receiver for video must be able to drive a 50 ohm load whereas audio reciever only needs to drive a 10 K ohm load.
By the way, there are products made to do what you want over fiber optic links.
75 ohm.
For a simple experiment you can amplitude-modulate the laser beam intensity, but for any kind of quality you will need an extremely linear FM modulator. Broadcast quality color videotape started in 1957 with a carrier frequency range of 5.5 to 6.5 MHz. Yes, 4 MHz information on a 6 MHz carrier. Yes, it worked.
Things evolved up to High-band color in the 60's using a 10 MHz carrier, still a very poor modulation index. They got away with it because the noise floor of the tape was so high that a higher carrier frequency did not improve the quality of the recovered signal. With the components and tech that are available today, I'd start up around 20 MHz.
ak
For a simple experiment you can amplitude-modulate the laser beam intensity, but for any kind of quality you will need an extremely linear FM modulator. Broadcast quality color videotape started in 1957 with a carrier frequency range of 5.5 to 6.5 MHz. Yes, 4 MHz information on a 6 MHz carrier. Yes, it worked.
Things evolved up to High-band color in the 60's using a 10 MHz carrier, still a very poor modulation index. They got away with it because the noise floor of the tape was so high that a higher carrier frequency did not improve the quality of the recovered signal. With the components and tech that are available today, I'd start up around 20 MHz.
ak
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Yes 75 ohms, not 50.
I have never modulated a diode Laser. Do you have any feel for how fast a typical Laser, such as a Laser pointer, can be modulated? I've heard of some gas Lasers being modulated at as high as 100 MHz.
Laser diodes run the core of the internet at gigahertz speeds, but they cost more than a laser pointer. A 10-cent red LED turns on in about 10-20 ns and off in 50 ns (working from memory).
In the 70's I worked nights at a TV station. We cannibalized an old videotape machine are replaced 100% of the electronics with contemporary circuits. Once we had the mod and demod working, we whipped up a visible LED link between the two (yup, bored). It worked well enough to show off.
ak
In the 70's I worked nights at a TV station. We cannibalized an old videotape machine are replaced 100% of the electronics with contemporary circuits. Once we had the mod and demod working, we whipped up a visible LED link between the two (yup, bored). It worked well enough to show off.
ak
